Explosive charge container



July 8,1958

R. D. MASON EXPLOSIVE CHARGE CONTAINER Filed April 23, 1954 EXPLOSIVE CHARGE CONTAINER Richard D. Mason, Winnetka, Ill., assignor to Seismo graph Service Corporation, ofDelaware ApplicationApril 23, 1954, Serial No. 425,197

' 7 Claims. (Cl. 102-24 Tulsa, Okla., a corporation The present. invention relates tocontainers for explosive materials and more particularly to containers equipped-with facilities .for insuringcomplete detonation Z United States Patent Fig. 1 thereof, there is illustrated a charge or column of} explosive cartridges generally designated by the reference;

'of anumber of explosive cartridges when arranged in endvto-end relationship to form an elongated explosive column. P I

'One method of insuring complete detonation of a long 1 column of low sensitivity explosives of the type com-= monly used in seismic survey operations, mining, quarry- 7 ing andsimilar operations, is described and claimed in co-pending application Serial No. 746,578, filed May 7,

194.7,. by RobertfL. Klotz, Jr. and assigned 'to the same "assignee as the present invention, which application .:-matured into BatentN'o. 2,683,414 on July 13, 1954. The

above identified application discloses an arrangement whereina plurality of cartridges, at least some of which have jet forming cavities in one'end, are aligned in end- I tor-endrelations'hip to form an explosive. column of the desired; length. When the column is detonated,- the jet forming cavity in the end of each cartridge of the column- I which. is .so equipped produces an explosive jet elfect which is directed intothe next. adjacent cartridge, thereby tostrengthen and revitalize the detonating' wave traveling along the column.= Thev presentinvention'relatesto improyedexplosive charge containers for instrumenting the arrangement disclosed in the identified Klotz application in} a; simple and economical manner.

.ltis an object" of the present invention'to provide an '7 "improved container assembly for explosive charges.

1 It, is another object of the present invention to provide an' improved container for explosive charges which is so fonned and arranged. that when. two cartridges are placed, inend-to-end(relationship ajet forming cavity is provided in-one end wall of one of the cartridge con-' tainers for producing an explosive jet upon detonation of the. one cartridge which is directed into the adjacent end of the other cartridge. I I V, a v According toa'further object of theinvention; one

the. manner described above, any foreign matter such as dirt, water, etc; which may inadvertently get' between the adjacent ends of any pair of cartridges, in many cases has from one'cartridgeto the adjacent cartridge to'the point where the adjacent cartridge is not detonated. Any such undetonatedexplosive' material used in a givench arge'isf not only Waste ofrmaterial, but, in addition, constitutes: an'

7 after .the blasting on endwall of thepresent improved explosive containe'r is v provided with end wall parts defining an" inwardly ex tending stand-off chamber which is adapted; to be'axially aligned-with the jet forming cavity in theopposite end wall of an identical container when'thetwo containersare arranged in end-to-endrelationship. i

. 'In accordance with still another' ob ject oi the inven- ,tioin'ithe present improved container ,is provided. with exceedingly simple facilities forzr'naintaining twoor more staclcedf cartridges in axial alignment so. that t-hejet form ing cavity provided in oneend of onecartridge container 7 is aligned with vthe stand-01f cavity or chamber provided in theoppositeend. of the. abuttingcartridge container. f Further objects and advantages'of the present invention "will becomeapparent as the following, descriptionproj' reeds, and the features of noveltywhich: characterize iinvention will be pointed out with particularity in. the, claims-annexed to and forminga partofthisspecification.

. For; a better understanding; of the. present invention,"

'2 reference may be had to the accompanying drawing, in which: Fig. l is a view'of a charge formed of a plurality of cartridges embodying containers characterized by 'the features of the present invention and aligned in end-toend relationship within a shot, hole;

.Fig. 2 is an enlarged sectional view taken along the;

line 2-2 in Fig. 1 showing one positional arrangement of the aligned cartridges; v I v Fig. 3 is a sectional view taken along the line 33 in, V 7 Fig. 4 is a view, partially in section, taken alongthe line-44 in Fig. 2; and

Fig. 5 is a fragmentary sectional view illustrating'ai modified embodiment of the present improved container;

Referring now to the drawing, and more particularly'to numeral 10 and aligned within a shot hole 11 drilled into the, earth. This charge or column 10 of explosive-car; tridges comprises a plurality of individual cartridges 12 positioned in end-to-end relationship within the shot hole;

If required by the particularapplication involved, these cartridges may be fastened together in any well known. manner, such as by taping/f lathing, stringing? pegging and the like, or, as is even more common, each Fatented July 8,

of the cartridges 12 may be dropped endwise into the shot hole 11 to form the column'10.

It is well known that'the detonation or propagation, wave traversing a column of explosive material tends to become less intense the further the detonating wave travels 1 from the point of initiation. vThis tendencyincreasesas the diameter of'the explosive column decreases. It also increases as the pressure, such as the fluid tampingpres f sure used in the shot hole increases,v and as the sensitivity ofthe explosive material used is decreased. As a conissectionalized, as by stacking a number of cartridges in sequence, only a portion of the explosive material pro-' vided' in a long column of low sensitivity explosive ma terial may-beexploded in response to' detonation of the columnat one end thereof. Moreover, when the column 4 the eifect of attenuating thedetonating wave. as it travels} explosives 'haz'ard which remains shooting operation is completed. I

The :problem outlined above solved a and economical manner by packagingfthe low sensitivity j explosive material 13 in containers l lcharacterizedby the features of the present invention. i Briefly, each container'f 14 is provided with end wallpart s which defineia conical" jet forming cavity 14a in the explosive-material 13*dis-g posed ,atthe bottom of each cartridge, and a cylindrical stand-elf chamber'14b in the explosive materialdisp'osed V at the top of: each cartridgei' More 'specifically,ifeech} container 14 comprises an elongated-cylindrical" body" portion 15 having a bottom end closure Wall 16 integrally formedtherewith and a top end closure member 17. The

formed portion 18 shaped to define a cavity 14a of the desired configuration. The lower end wall 16 of the container 14 obviously seals the container and prevents the explosive material from' entering the cavity 14a. As shown in the drawing, the cavity 14a has a conical configuration, although it will be evident to those skilled in the art that other configurations may be used, if desired. Many explosive cartridges presently sold commercially include a container 14 made of heavy cardboard or other non-metallic material having relatively little strength. It the container 14 is comprised of such material, it may be difiicult to maintain the desired shape of .the formed bottom wall portion 18. Accordingly, if the container 14 is made of such material a backing or liner plate 19 should be provided within the container 14. This plate is shaped to define the desired configuration for the cavity 14a and functions to reinforce the formed bottom wall portion 18 of the container and thus maintain the shape of the cavity.

. For the purpose of defining the stand-oil chamber 14b in the explosive material 13 provided at the upper end of each cartridge, the end closure member 16 sealing the upper end of the cartridge is provided with a downwardly formed portion 20 located at the center of the closure member. This formed portion of the closure member is illustrated as being of generally cylindrical configuration and, as shown, is adapted to register with the jet forming cavity 14a in the adjacent abutting cartridge when two or more cartridges are stacked or otherwise arranged in end-to-end relationship. In order to retain the stacked cartridges in axially aligned positions, so that the jet forming cavity 14a of each cartridge is in exact registry with the stand-off chamber 14b of the adjacent abutting cartridge, each of the closure members 17 is provided with an upstanding flange 21 for receiving the bot tom end wall 16 and the bottom portion of the container'14Iof the next uppermost cartridge 12. If desired, the upstanding flange 21 may be provided with internal threads, not shown, which coact with external threads provided at the bottom portion of the next uppermost container 14 to hold the two adjacent containers in connected relationship. As will be understood, the height of the chamber or well 14b defined by the formed wall portion 20 of the closure member 17 for each cartridge defines the stand-01f distance between the explosive material of the cartridge and the mouth of the jet forming cavity 14a provided in the abutting cartridge.

Although the formed portion 18 of the container 14 is V illustrated as having a conical shape, other similar shapes symmetrical about the axis of the cartridge, such as hemispherical or hernispheroidal, may be employed. In any case the purpose of providing the bottom wall formations to define the cavities 14a is to permit the-well known Munroe Efiect, i. e., directionalized explosive eifect, to be obtained. In other words, each cavity 14a acts to redistribute and concentrate the energy of that portion of the explosive material 13 nearest the cavity 14a. Each stand-oil chamber 14b permits the explosive jet to form. More specifically, the explosive forces developed at the surface of the formed Wall portion 18 of each cartridge 12, meet at the axis of the cavity 14a within the cavity 14b of the next lower cartridge and add vectorially, thereby to effect concentration of explosive energy into a jet which is directed into the explosive material of the next lower cartridge.

In order to insure that the shapes of the cavities 14aand 14b in the ends of each cartridge will be preserved, it is desirable to employ relatively rigid material, such as heavy cardboard or the like, in the construction of the end closure member 17 and the container body portion 15. Alternatively, the backing or liner plate 19 may be used to insure preservation of the desired configuration of each jet forming cavity 14a. The annular flanges 17a asaaozss therewith in order to insure that foreign material, such as the water used for tamping, will not enter the cavities 14a and 14b and reduce the effectiveness of the cavitated charge or nullify it entirely. Alternatively, and as illustrated in Fig. 5 of the drawing, frangible sealing disks 21 and 22 may be adhesively secured to the container wall 16 and the wall of the closure member 17 of each container 14 to cover and seal the cavities 14a and 14b thereof against fluid entry into these cavities.

In use, the cartridges 12 are arranged in end-to-end relationship with the apexes of the cone-shaped cavities 14a pointing toward the point of detonation of the column thus formed. Thus when the cartridges are arranged in the manner shown in Fig. 1, with a detonating cap or fuse 23 located at the top of the column and connected to the fuse wires indicated at 24, the apexes of the cavities 14a in the cartridges 12 point upwardly toward the cap 23. The cylindrically shaped cavity or chamber 14b in the top cartridge 12 of the column may be used to house the detonating cap 23. Under certain conditions, it may be desirable to detonate the charge from the bottom, in which case the entire column would be rotated through an angle of one hundred and eighty degrees and the detonating cap 23 would be inserted in the cylindrical cavity 14b in the bottom of the lowest cartridge in the column. It will be understood that the column may also be detonated from an intermediate point. In such case, however, the apexes of the conically shaped cavities 14a should all point toward the cap 23 regardless of its location in the column. Thus, the detonating cap is disposed in the middle of the explosive column, then the apexes of the cavities 14a above the cap should point downwardly toward the cap, and the apexes of the cavities 14a below the cap should point upwardly toward the cap.

By employing the improved container arrangement described above, a high intensity detonation jet is formed and directed from each cartridge into the next succeeding cartridge in the column which insures complete detonation of all explosive material in the column. Also by employing the present improved containers, it is possible to use less sensitive explosives which are less expensive and far less dangerous to handle. Furthermore, much longer columns may be detonated and propagation of the explosive effect is assured even Where there is a substantial space between thecartridges, which space might be filled with air, water, mud or the like.

It will be apparent to those skilled in the art that the present invention is not limited to the particular construction shown but that changes and modifications may be made without departing from the spirit and scope of the present invention. It is aimed in the appended claims to cover all such changes andmodifications.

What is claimed as new and desired to be secured by Letters Patent of the United States is:

l. An explosive charge comprising a plurality of explosive cartridges arranged in end-to-end relationship to form a column of cartridges each containing explosive material, at least one of said cartridges having a unitary endstructure closing one end and including structure defining a closed shaped jet forming cavity extending into the explosive material in said one cartridge for producing a jet explosive efiect directed into the adjacent end of the next cartridge, said adjacent end of said next car- V cavity for directing the jet explosive effect into said next cartridge, thereby insuring complete detonation of all of said cartridges.

2. Anexplosive charge comprising a plurality of explosive cartridges arranged in end-to-end relationship to form a column of cartridges each containing explosive material,

and a detonating means for detonating said charge located at a predetermined point in said column, at least one of said cartridges having a unitary endclosure at the end thereof remote from said detonating means, said Closure including integral structure extending into the explosive material in said cartridge in order to define a shaped jet' torming cavity therein for producing a jet explosive elfect m a direction away from said point and into the adjacent end of the next cartridge, said adjacent end of said next cartridge having a unitary end closure including an integral structural element extending into the explosive matenal in said adjacent cartridge and defining a shaped stand-off cavity aligned with and ofa different shape than the first mentioned shaped cavity for directing the jet explosive efifect into said next cartridge.

3.An explosive charge comprising a plurality of explosive cartridges arranged in end-to-end relationship to I form a column of cartridges each containing explosive material, at least one of said cartridges having a unitary "end closure which includes an integral structural element extending into the explosive material in said one cartridge in order to define a cone-shaped jet forming cavity for producing a jet explosive elfect directed into the adjacent end of-the next cartridge, said adjacent end of said next cartridge having a unitary end closure which includes an inte-- gral structural element extending into the explosive material in said adjacent cartridge and defining a cylindrically shaped stand-01f chamber having a diameter equal to that of the base of the cone-shaped cavity and aligned with the first mentioned cone-shaped cavity for directing the jet explosive effect into said next cartridge, thereby insuring complete detonation of said cartridges.

. 4. An explosive charge comprising a plurality of explosive cartridges arranged in end-to-end relationship to form a column of cartridges each containing explosive material, at least one of said cartridges havinga unitary closure atone end thereof which includes an integral structural. element extending into the explosive material in said one cartridge in order to define a shaped jet forming cavity therein for producing a jet explosive efiect directed into the adjacent end of the next cartridge, said adjacent end of saidnext cartridge having a unitary clof j sure therefor which includes an integral structural element extending into the explosive materialin said adjacent cartridge in order to define a shaped stand-0E chamber aligned with and of difierent shape than the first mentioned shaped cavity'for directing the jet explosive effect into said next cartridge, thereby insuring complete detonation of all of v said cartridges, one of said closures having formed thereona flange surrounding the end of the adjacent cartridge in the column in order to align each of the jet forming cavities and its associated stand-ofi chamber.

5. An explosive charge comprising a'plurality of ex-v plosive cartridges arranged in end-to-end relationship to form a column of cartridges .each containing explosive material, at least one of said cartridges having a unitary closure at one end which includes an integral structural element extending into the explosive material in said one cartridge in order to define a cone-shaped jet forming cavity for producing a jet explosive efiect directed into the adjacent end of the next cartridge, said adjacent end of saidnext cartridge having a unitary closure which includes an integral structural element extending into the by insuring complete detonation of all o f'said cartridges,

one of said closures having formed thereon a flange sur rounding the end of the adjacent cartridge in the column in order to align the jet forming cavity and its associated stand-off chamber.

6. An explosive charge comprising a plurality of explosive cartridges arranged in end-to-end relationship to form a column of cartridges each containing explosive material, and a detonating means for detonating said charge located at a predetermined point in, said column, at least one of said cartridges having a unitary end closure member which includes an integral structural ele-.

ment extending into the explosive material at" an endof the cartridge remote from said detonating means inorder to define a shaped jet forming cavity. for producing a jet explosive effect in a direction away from said point and into the adjacent end of the next cartridge, said ad-' jacentend of said next cartridge having a unitary closure member which includes an integral structural element extending into the explosive material in said adjacent cartridge and defining a stand-01f chamber aligned with and of diflferent shape than the first mentioned shaped cavity for directing the jet explosive efiect into said next cartridge, one of said closure members having formed thereon a flange surrounding the end of the adjacent cartridge in the column in order to align the jet forming cavity and its associated stand-oflz chamber.

7. An explosive charge comprising aplurality of explosive cartridges arranged in end-to-end' relationship to] form a column of cartridges each containing explosive material, and a detonating means ,fordetonating .said charge located at a predetermined point in saidcolumn, at least one of said cartridges having a-unitary end closure member which includes an integral structural. element extending into the explosive material in an end of said one cartridge remote from said detonating means in order to define a cone-shaped jet forming cavity for producing a jet explosive effect in a direction away from said point and into the adjacent end of the next cartridge,

said adjacent end of said next cartridge having a unitary endclosure member which includes an integral structural element extending into the explosive material in said *adjacent cartridge and defining, a cylindrically shaped stand-off chamber aligned with and having a diameter 7 equal to that of the base of said shaped cavity for directing the jet explosive efiect into said next'cartridge, one

explosive material in said adjacent cartridge and defining' a cylindrically'shaped stand-01f chamber having a diameter equal to that of the base of the cone-shaped cavity and I aligned with the first mentioned shaped cavity for directing- "the jet explosive eiiect into said next cartridge, thereof said closure members having formed thereon a flange surrounding the end of the adjacent cartridge in'the column in order to align the jet forming cavity audits associated stand-oif chamber; 7 j

V I References Cited in the file of patent UNITED STATES PATENTS Germany Oct- 6, 1952 

